Grammatical Characteristics of Vietnamese and English in Developing Bilingual Children.

Purpose Defining parameters for typical development in bilingual children's first and second languages can serve as the basis for accurate language assessment. This is the first study to characterize Vietnamese and English grammatical development in a sample of bilingual children. Method Participants were 89 Vietnamese-English bilingual children, aged 3-8 years. Children completed story retell tasks in Vietnamese and English. Stories were transcribed and analyzed for grammaticality, error patterns, subordination index, and types of subordinating clauses. Of key interest were associations with age and identifying developmental patterns that were shared across languages or unique to a given language. Results Age correlated with more measures in English than in Vietnamese, suggesting that older children had higher grammaticality and greater syntactic complexity in English than younger children. Children also produced greater syntactic complexity with age in Vietnamese, but not higher grammaticality. There were a set of error patterns shared across languages (e.g., object omission) and patterns specific to each language (e.g., classifier errors in Vietnamese, tense errors in English). While children produced nominal, adverbial, and relative clauses in Vietnamese and English, the proportion of each clause type differed by language. Conclusions Results from this typically developing sample provide a reference point to improve clinical practice. Characterizing developmental patterns in sentence structure in Vietnamese and English lays the groundwork for investigations of language disorders in this bilingual population.